A magnetron includes a cathode and an anode, the anode usually being of copper. In a presently known method of making the anode, a cylindrical copper block is machined to produce a central anode bore. The cylindrical block is shown at 1 in FIGS. 1 and 2 respectively which are transverse and longitudinal sections respectively of a magnetron anode. Conventionally, equidistant slots 2 are broached in the surface of the bore in a direction parallel to its longitudinal axis and vanes 3 are then fitted into the slots 2 using a purpose-designed jig. End space fillers 4 and 5 (See FIG. 2) are located on each side of the vanes 3 and the assembly is then brazed together in a furnace.
This known method of producing magnetron anodes is relatively time-consuming, and satisfactory accuracy in locating the vanes and slots may be difficult to achieve, especially where the magnetron is small.